The objective is to delineate the metabolism and structure of polysaccharides at the molecular and submolecular level. We are particulary concerned over the interrelationship between the mechanism by which enzymes act and the physical and chemical fine structure of the polysaccharides. We have found that sparsely substituted substrates can be used to direct the substrate into a specific binding mode at the enzyme binding site. This will permit us to identify the specific groups on the substrate responsible for substrate bindings and to learn whether they function as H-bond donors or acceptors. We will attempt to trap or identify covalent intermediates (presumably glycosyl enzyme esters or reactive N-glycosides). We will look for torsion of the reactive monosaccharide unit as a mechanistically important feature of substrate binding. By using specific inhibitors (transition state analogs, affinity substrates) we will probe the detailed organic reaction mechanisms for the various types of enzymes. A part of our total effort will be devoted to the eludication of polysaccharide conformation and to methodology. It is expected that these studies will be useful in understanding the normal and abnormal metabolism of polysaccharides and of biopolymers in general.